1. Field of the Invention
The present invention relates to a disc cartridge which receives a disc-like recording medium such as an optical disc, a photomagnetic disc and the like therewithin.
2. Description of the Prior Art
Conventionally, the discs such as the optical disc and the like are used for a disc-like recording medium- These discs are frequently used in a state of being received within the disc cartridge for the purpose of preventing a recording or reproducing error due to an attachment of oils and fats on a recording surface thereof.
In this case, the disc-like recording medium is structured such that in the case that a recording density is fixed, a recording capacity of course becomes greater as a diameter thereof becomes greater. On the contrary, in the case of using the disc-like recording medium mentioned above as a recording medium for a portable recording and reproducing apparatus, for example, a video camera and the like, a compact disc is excellent in portability. Accordingly, there is a case that the disc used for a portable apparatus has a different diameter from the disc used for a stationary apparatus. At this time, a small-sized disc cartridge is of course used for a disc cartridge used for the portable disc. In the case that a recording method is the same and only a shape of the disc is different, if it is possible to mount the disc to the recording and reproducing apparatus, it is possible to record or reproduce by means of recording and reproducing means provided in the recording and reproducing apparatus. Therefore, it is possible to record and reproduce the disc used for the portable apparatus in the stationary recording and reproducing apparatus by taking out only the disc from the compact disc cartridge and replacing in the disc cartridge having the same outer shape as that of the disc cartridge in the stationary apparatus.
Further, in an optical disc, a recording operation is sensitive to a dirt and a reproducing operation is relatively strong to a dirt, so that in the case of performing only a reproducing operation without again performing a recording operation in the once recorded disc, there exists a system in which a disc is taken out from the disc cartridge and only the disc can be treated.
Because of the reasons mentioned above, there is a requirement of inserting and removing the disc with respect to the disc cartridge. As a structure of taking out the disc from the disc cartridge, for example, there is a method of arranging a disc insertion and removal portion in a part of the disc cartridge as shown in Japanese Patent Unexamined Publication No. 5-242626.
A description will be given of a structure for taking out the disc from the disc cartridge in accordance with the conventional art with reference to FIG. 9. A disc insertion and removal port 12 is provided on a surface opposite to a surface on which a shutter 3 is arranged, and a disc insertion and removal port opening and closing member 10e is arranged there. Normally, the disc insertion and removal port opening and closing member 10e is structured such that a locking hook 6e is fitted to a locking hole 7e arranged in the disc cartridge and the disc insertion and removal port 12 is closed. At a time of taking out a disc 4, the locking hook 6e is removed from the locking hole 7e and the disc insertion and removal port opening, closing member 10e is rotated around a rotational support point 8e and the disc insertion and removal port 12 is opened, so that the disc 4 is inserted and removed.
Further, another conventional embodiment is shown in FIG. 10. In the conventional embodiment shown in FIG. 10, a disc insertion and removal port opening and closing member 10f is structured such as to be capable of being taken out from the disc cartridge 1. Further, at a time of attaching the disc insertion and removal port opening and closing member 10f, the disc insertion and removal port opening and closing member 10f is locked by a fitness between a locking hook 6f and a locking hole 7f, thereby preventing an erroneous falling off.
In the disc cartridge as mentioned above, in the case of using the disc cartridge receiving disc once taken out therewithin in the recording and/or reproducing apparatus corresponding to the cartridge, it is necessary that the apparatus detects the fact of being taken out. This is necessary for the purpose of inhibiting a recording operation of the disc which has been taken out to an outer portion or more frequently performing a recording check since a recording operation is sensitive to a dirt in the optical disc as mentioned above. A method of detecting a history of taking out the disc will be described below with reference to FIG. 11. FIG. 11 shows a structure of opening and closing the disc insertion and removal port 12 by a disc insertion and removal port opening and closing member 10i in the same manner as that of the embodiment shown in FIG. 9, thereby inserting and removing the disc. A locking hook 6i and a locking hole 7i are fitted to each other and the locking member 11 is fitted to the locking hole 9, whereby a locking of the disc insertion and removal port opening and closing member 10i is performed. When the locking hook 6i is removed from the locking hole 7i, the locking hook 6i is elastically deformed in an inner direction of the disc cartridge, so that a fitting can be again performed even after once removed. On the contrary, when removing the locking member 11 from the locking hole 9, the locking member 11 is broken out from the disc insertion and removal port opening and closing member 10i. 
When opening the disc insertion and removal port opening and closing member 10i, it is necessary to release these two kinds of locking means, however, when opening the disc insertion and removal port opening and closing member 10i, the locking member 11 becomes in a broken state, so that it is possible to recognize a history of taking out the disc by detecting the broken state.
As mentioned above, in the conventional and reference arts, when taking out the disc from the disc cartridge, the disc takeout history is definitely left in the disc cartridge.
However, as a purpose of taking out the disc, in addition to the case of using a simple disc exclusively for reproducing the disc, there is a case of using the disc with moving the disc between the disc cartridges. In this case, since a user does not positively handle the disc, there is a little possibility that a dirt is attached to the disc surface. Further, it can be avoided to be directly in contact with the disc by closely attaching the insertion and removal ports of the disc cartridge to each other and moving the disc, so that a dirt is not attached. Even in this case, when the disc take-out history is left, an impossible recording treatment or an excessive recording check is performed although no dirt is attached to the disc, so that a usability of the disc is deteriorated.
U.S. application Ser. No. 09/233,205 , now U.S. Pat. No. 6,349,087, discloses the use of a disc holder for holding the disc and which is insertable and removable from the disc cartridge together with the disc. FIG. 12 shows a disc insertion and removal member in accordance with the copending application, wherein a disc insertion and removal opening and closing member 10g is structured such as to be capable of being taken out from the disc cartridge 1. At a time of attaching the disc insertion and removal port opening and closing member 10g, the disc insertion and removal port opening and closing member 10g is locked by a fitness between a locking hook 6g and a locking hole 7g. It is structured such that the disc 4 can be taken out of the disc cartridge 1 by a disc auxiliary member 2 which changes and holds the disc as described in the copending application and is arranged in the disc insertion and removal port opening and closing member 10g at a time of taking out the disc insertion and removal opening and closing member 10g. 
FIG. 13 illustrates another form of a disc holding member wherein a disc insertion and removal opening and closing member 10h is structured such as to be capable of being taken out from the disc cartridge 1. At a time of attaching the disc insertion and removal port opening and closing member 10h, the disc insertion and removal port opening and closing member 10h is locked by a fitness between a locking hook 6h and a locking hole 7h. It is structured such that the disc 4 can be taken out of the disc cartridge 1 in a state of being held by a disc holding member 5 which is a variation of the disc auxiliary member 2 and is arranged in the disc insertion and removal port opening and closing member 10h when taking out the disc insertion and removal opening and closing member 10h. 
An object of the present invention is to provide a disc cartridge structured such that a history of taking out a disc is left in the disc cartridge in the case of taking out the disc for the purpose of using the simple disc and is not left in the disc cartridge in the case that a use does not positively handle the disc such as a movement of the disc between the disc cartridges.
In order to achieve the object, in accordance with the present invention, there is provided a disc cartridge in which a disc insertion and removal port can be opened and closed by an insertion and removal port opening and closing member, and locking means for locking the insertion and removal port opening and closing member when the insertion and removal port opening and closing member is closed and locking cancellation preventing means for preventing the locking means from canceling the locking of the insertion and removal port opening and closing member are arranged in the disc cartridge.
Further, the locking cancellation preventing means is formed in a shape structured such as to cover at least a part of a portion in which the locking means is exposed to an outer portion of the disc cartridge.
Still further, at least a part of the locking cancellation preventing means is irreversibly displaced so as to expose at least a part of the locking means which the locking cancellation preventing means covers to an outer portion of the disc cartridge.
Furthermore, at least a part of the locking cancellation preventing means is arranged on a moving path necessary for the locking means to cancel the locking.
Moreover, the locking cancellation preventing means is irreversibly displaced out of the moving path from the moving path of the locking means and the locking means is made movable so as to cancel the locking.
Further, the locking cancellation preventing means is irreversibly displaced out of the moving path from the moving path of the locking means and the locking means is moved in a state of displacing the locking cancellation preventing means so as to cancel the locking.
Still further, the history of the insertion and removal of the disc can be recognized by detecting the state of the locking cancellation preventing means.